US4725671A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Collagen membranes for medical use
Assignee: Angiotech Biomaterials Corp
•
Filing: 1986-02-04
•
Granted: 1988-02-16
•
Expires: 2006-02-04
Abstract
Abstract Collagen membranes with desired properties are prepared by using a variety of gel-forming techniques in combination with methods for converting the gels to solid forms. The properties of these membranes or other solid forms may be further altered by cross-linking the collagen preparation either after formation of the membrane or gel, or most preferably by mixing cross-linked collagen with solubilized collagen in the original mixture used to create the gel.
Inventors
- 👤 George Chu
- 👤 John R. Daniels
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 02:15
CPC Classifications
A; A61; A61L; A61L27/00; A61L27/50; A61L27/52; A61F; A61F2/00; A61F2/02; A61F2/04; A61F2/06; A61F2/08; A61F2/10; A61L26/00; A61L26/0009; A61L26/0028; A61L26/0033; A61L26/0061; A61L26/008; A61L27/14; A61L27/22; A61L27/24; C; C08; C08L; C08L89/00; C08L89/04; C08L89/06; A61F2310/00; A61F2310/00005; A61F2310/00365; Y; Y10; Y10S; Y10S128/00; Y10S128/08; Y10S602/00; Y10S602/90
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
37 words
A process for preparing a collagen membranous material which comprises compressing a collagen gel matrix to form a fiber network, and drying said network, wherein the compression is conducted by absorbing the aqueous fraction from the gel.
Claim 2
Dependent Claim
37 words
A process for preparing a collagen membranous material which comprises compressing a collagen gel matrix to form a fiber network, and drying said network, wherein the compression is conducted by absorbing the aqueous fraction from the gel.
Claim 3
Dependent Claim
25 words
The process of claim 1 wherein the compression is conducted by absorbing the aqueous fraction from the gel by sandwiching the gel between absorbent materials.
Claim 4
Dependent Claim
16 words
The process of claim 1 which further includes the steps of washing said network, and redrying.
Claim 5
Dependent Claim
19 words
The process of claim 1 which further indicates the step of cross-linking the membranous material after said compression step.
Claim 6
Dependent Claim
89 words
A process to prepare a gel useful for conversion to a collagen membranous material which comprises cooling atelopeptide collagen-in-solution to approximately 4° C., treating the cooled solution with a buffer solution precooled to approximately 4° C., to obtain a mixture with a pH of approximately 7 and an ionic strength of approximately 0.05, and incubating the mixture at about 20° C. for about 16-20 hours. wherein the collagen in solution is mixed with a suspension of cross-linked collagen to obtain a percentage of cross-linked collagen of 10% to 95%.
Claim 7
Dependent Claim
89 words
A process to prepare a gel useful for conversion to a collagen membranous material which comprises cooling atelopeptide collagen-in-solution to approximately 4° C., treating the cooled solution with a buffer solution precooled to approximately 4° C., to obtain a mixture with a pH of approximately 7 and an ionic strength of approximately 0.05, and incubating the mixture at about 20° C. for about 16-20 hours. wherein the collagen in solution is mixed with a suspension of cross-linked collagen to obtain a percentage of cross-linked collagen of 10% to 95%.
Claim 8
Dependent Claim
77 words
A process to prepare a gel useful for conversion to a collagen membranous material which comprises mixing, at ambient temperature, atelopeptide collagen-in-solution with sufficient salt/buffer solution to obtain a mixture with a pH of approximately 7 and of approximately physiological ionic strength, and incubating the mixture at about 37° C. for 16-20 hours, wherein the collagen in solution is mixed with a suspension of cross-linked collagen to obtain a percentage of cross-linked collagen of 10% to 95%.
Claim 9
Dependent Claim
77 words
A process to prepare a gel useful for conversion to a collagen membranous material which comprises mixing, at ambient temperature, atelopeptide collagen-in-solution with sufficient salt/buffer solution to obtain a mixture with a pH of approximately 7 and of approximately physiological ionic strength, and incubating the mixture at about 37° C. for 16-20 hours, wherein the collagen in solution is mixed with a suspension of cross-linked collagen to obtain a percentage of cross-linked collagen of 10% to 95%.
Claim 10
Dependent Claim
115 words
A process to prepare a gel useful for conversion to a collagen membranous material which comprises precooling atelopeptide collagen-in-solution to about 4° C., mixing the cooled collagen in solution with a buffer solution, precooled to about 4° C. to obtain a mixture with a pH of approximately 7 and ionic strength of about 0.05, and centrifuging the mixture at about 8,000×g to 13,000×g for 1-2 hours at about 4°-25° C., immediately after mixing to obtain a supernatant, recovering the supernatant, and incubating the supernatant at about 20° C. for 16-20 hours, wherein the collagen in solution is mixed with a suspension of cross-linked collagen to obtain a percentage of cross-linked collagen of 10% to 95%.
Claim 11
Dependent Claim
115 words
A process to prepare a gel useful for conversion to a collagen membranous material which comprises precooling atelopeptide collagen-in-solution to about 4° C., mixing the cooled collagen in solution with a buffer solution, precooled to about 4° C. to obtain a mixture with a pH of approximately 7 and ionic strength of about 0.05, and centrifuging the mixture at about 8,000×g to 13,000×g for 1-2 hours at about 4°-25° C., immediately after mixing to obtain a supernatant, recovering the supernatant, and incubating the supernatant at about 20° C. for 16-20 hours, wherein the collagen in solution is mixed with a suspension of cross-linked collagen to obtain a percentage of cross-linked collagen of 10% to 95%.
Claim 12
Dependent Claim
17 words
The process of claim 5 wherein the gel is converted to the collagen membranous material by compression.
Claim 13
Dependent Claim
18 words
The process of claim 8 wherein the compression is conducted by absorbing the aqueous fraction from the gel.
Claim 14
Dependent Claim
17 words
The process of claim 6 wherein the gel is converted to the collagen membranous material by compression.
Claim 15
Dependent Claim
18 words
The process of claim 10 wherein the compression is conducted by absorbing the aqueous fraction from the gel.
Claim 16
Dependent Claim
17 words
The process of claim 7 wherein the gel is converted to the collagen membranous material by compression.
Claim 17
Dependent Claim
18 words
The process of claim 12 wherein the compression is conducted by absorbing the aqueous fraction from the gel.
Claim 18
Dependent Claim
10 words
A collagen gel prepared by the process of claim 5.
Claim 19
Dependent Claim
10 words
A collagen gel prepared by the process of claim 6.
Claim 20
Dependent Claim
10 words
A collagen gel prepared by the process of claim 7.
Claim 21
Dependent Claim
11 words
A collagen membranous material prepared by the process of claim 8.
Claim 22
Dependent Claim
11 words
A collagen membranous material prepared by the process of claim 10.
Claim 23
Dependent Claim
11 words
A collagen membranous material prepared by the process of claim 12.
References Cited (Backward Citations)
US2934446A
Cited
JPS4939174A
Cited
US4140537A
Cited
US4242291A
Cited
US4412947A
Cited
US4453939A
Cited
EP0089152A1
Cited
EP0092200A2
Cited
US4600533A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-02-15 | 1991-08-17 | 1992-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-02-15 | 1995-08-17 | 1996-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-02-15 | 1999-08-17 | 2000-02-16 | $7700.00 | Window Closed / Lapsed |